Digital PI control for interleave PFC boost converter

In recent years, improving of power factor and reducing harmonic distortion in electrical instruments are needed. In general, a current conduction mode boost converter is used for active PFC (Power Factor Correction). Especially, an interleave PFC boost converter is used in order to make a size compact, make an efficiency high and make noise low. In this paper, a PI digital controller for suppressing the change of step response characteristics and variation of output voltage at a load sudden change with high power factor and low harmonic is proposed. Experimental studies using a micro-processor for controller demonstrate that the PI digital controller is effective to improve power factor and to suppress output voltage variation and is more advantageous to control the current of the sum of each phase in hardware.